The present invention relates to a spraying device for headlamp-cleaning systems for motor vehicles, and, more particularly, to a device comprising a nozzle carrier, an actuating device for moving the nozzle carrier in a telescopic manner out of a retracted rest position in a cylindrical receiving and guide tube retracted in a vehicle body into an operating setting in an area in front of a diffusing screen of a vehicle headlamp, a flexible line operatively connecting the nozzle carrier to a washwater reservoir, a head end of the nozzle carrier is configured, in a direction of the vehicle exterior, as a cover plate which, in the retracted rest position, produces a rectilinear continuation of a vehicle contour and comprises a nozzle holder attached to the head end of the nozzle carrier and at least one cleaning nozzle which is directed, in the operating setting, towards the diffusing screen.
A variety of fixed-mounted, but also extensible, headlamp-cleaning nozzles are known. The fixed-mounted cleaning nozzles are generally located on bumpers at a relatively great distance from the diffusing screen, thereby enabling a satisfactory cleaning effect to be obtained only with a high water consumption. Moreover, as a result of this exposed position, the nozzles are subject to a considerable risk of damage. Soiling and, in winter, freezing-up of the nozzles prevent them from functioning as intended.
From German Offenlegungsschrift 24 55 294 discloses a headlamp-cleaning system for vehicles exhibiting a spraying device which can be moved from the vehicle body out of a retracted rest position into an operating setting. The spraying device comprises a flexible hose which, in the rest position, is rolled up in a spiral shape and is housed in a recess in the front bumper and which can be stretched by a pressure device so that, in the operating setting, the cleaning nozzle fitted to the end of the hose is pointing at the diffusing screen.
A variant of the foregoing system provides for the spraying device a dimensionally stable tube, which, in the rest position, is fully retracted in the vehicle body and is moved into the operating position by an actuating device. These two cleaning systems are very space-consuming and, moreover, are very delicate and unstable, e.g. when the system is actuated in a strong slipstream.
German Patent Specification 35 18 685 describes a headlamp-cleaning system in which the spraying device is housed in the vehicle body in the area of the headlamp. The nozzle carrier with the nozzle, under the influence of pressure, is able to be extended in telescopic manner horizontally out of the vehicle body, so that the cleaning nozzle comes to be situated at some distance in front of and beneath the diffusing screen. This spraying device is of very compact configuration, so that it can be integrated into the headlamp housing. The operating setting of the cleaning nozzle is located, however, at a distance from the luminous disc comparable to that of the nozzles fixed-mounted on the bumper, from which the cleaning effectiveness suffers.
An object of the invention is to provide a compact spraying device, which can also be integrated into the headlamp housing, having improved functionality. The spraying device of the present invention is to exhibit a good cleaning effect, comparable to the prior art, combined with lower water consumption. In addition, another object is to improve the optical impression.
These objects have been achieved by a spraying device in which the section of the nozzle carrier which, in the operating setting, protrudes out of the vehicle body curves, in the operating setting, in the shape of an arc, such that the nozzle holder comes to be situated having at least one cleaning nozzle in an area just in front of the diffusing screen. This enables the cleaning nozzle to be moved easily out of the rest position below the headlamp into the operating setting directly in front of the diffusing screen, so that, in the cleaning procedure, the spray path is shortened, resulting in a clear decrease in water consumption combined with an equal or better cleaning effect.
One particular embodiment provides for the nozzle carrier to comprise two interconnected sections. In this configuration, the rear nozzle carrier section is an essentially cylindrical tube, while the front nozzle carrier section comprises a number of annular segments, which are connected on their underside by hinges running transversely to the longitudinal direction of the nozzle carrier. The width of the individual segments decreases in the direction of the top side of the nozzle carrier, so that a gap, which widens in the direction of the top side of the nozzle carrier, is created in each case between the segments. The construction of these gaps determines the radius of curvature in the operating setting.
An advantageous construction provides for the segments of the nozzle carrier to exhibit a toothed profile on their top side. As a result, the arrangement has a clearly increased stability in the operating setting, thereby guaranteeing problem-free usage even in a strong slipstream.
Advantageously, the two sections of the nozzle carrier are produced from the same material, in particular from a dimensionally stable and fracture-resistant plastic. In order to obtain an aesthetically pleasing appearance, the front section of the nozzle carrier which, in the operating setting, protrudes out of the vehicle body can be kept in the color of the car.
In a further embodiment, the nozzle carrier exhibits a control cable, the first end of which is anchored in the first segment adjoining the nozzle holder and which interconnects all subsequent segments. Its second end is connected to a spring force device.
In a configuration of the invention, the spring force device comprises a slide which is fitted displaceably on the rear nozzle carrier section and in an oblong recess in the receiving and guide tube and in which the second end of the control cable is anchored. To a suitably configured projection of the slide there is fitted an elastic element, in particular a helical spring, the second end of which is firmly connected to a projection of the receiving and guide tube.
In another configuration of the invention, the nozzle holder can be configured in one piece with the first segment.
A further construction provides for the actuating device for the movement of the nozzle carrier to comprise a drive motor driving at least one gearwheel fitted in a recess in the receiving and guide tube. This gearwheel engages in a lower part, configured like a rack, of the rear nozzle carrier section. By the rotation of the gearwheel, the nozzle carrier is moved out of the rest position into the operating setting and back again.
In a further design, the flexible line is a water hose which leads through the hollow interior of the nozzle carrier to the nozzle holder, to which it is firmly connected. The water hose exhibits, advantageously, an electric heating. The nozzle fitted in the nozzle holder can also be electrically heated.
In order, in the rest position, to prevent dirt and moisture from penetrating into the receiving and guide tube, the nozzle holder can be provided in the direction of the vehicle exterior with a sealing rubber gasket.
In another embodiment of the invention, the outside mouth of the receiving and guide tube is of funnel-shaped configuration. This ensures that the segments can be returned more easily into the receiving and guide tube.
In order to reduce the penetration of dirt and moisture in the operating setting also, in a further configuration the receiving and guide tube can be fitted in the vehicle body such that, sloping gently down in the direction of the vehicle exterior, it forms an acute angle, .alpha., to the vehicle's standing plane.